As someone who has been running for nearly 6 1/2 years now regularly and started doing so for mental health reasons, this book definitely peaked my interest. I have also read a fiction book by the author and enjoy her dry sense of humour and narration style. 
I think it was extremely well researched with a lot of psychological studies, which I also really liked as I studied Psychology at university. 
It does feel as though this book needed some editing however as it was quite repetitive in places. I just don't think there was enough content for a 280 page paperback. 
Overall I did enjoy my time reading this and would recommend it.
3 stars